Drill.



PATBNTBD FEB'. 17, 1903.

R. J. BROTHBM.

DRILL.A

APPLIGATION FILED JUNE s, 1902.

H0 MODEL.

2 SHEETS-SHEET l.

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UNITED STATES PATENT OFFICE.

RALPH J. BROTHEM, OF ENDRUM, MINNESOTA.

DRILL.

SPECIFICATION forming part of Letters Patent No. 721,009, dated February17, 1903.

(No model.)

To all whom it may concern:

Be it known that I, RALPH J. Beernem, a citizen of the United States,residing at Hendrum, in the county of Norman and State of Minnesota,have invented certain new and useful Improvements in Drills; and Idohereby declare the following to be a full, clear, and exact descriptionof theinvention, such as will enable others skilled in the art to whichit appertains to make and use the same.

My invention has for its object to provide an improvedexpansion-drill'or boring-tool especially adapted for boring wells; andto this end the invention consists of the novel devices and combinationsof devices hereinafter described, and dened in the claims.

The improved device is illustrated in the accompanying drawings, whereinlike characters indicate like parte throughout the several views.

As is Well known, it is customary in boring wells to employ a tubularcasing to prevent caving in of the small hole which is drilled. Thiscasing must follow closely after the tool, and the tool must of coursebe capable of drilling a hole large enough to freely admit the casing.The tool must also be capable of expansion and contraction, so that"when contracted it may be inserted and Withdrawn through the tubularcasing.

In my invention I accomplish the above results by simple and efficientmechanism, the preferred form of Which is illustrated in theaccompanying drawings.

Figure 1 shows my improved drill or boring-tool in side elevation. Fig.2 is a section on the line .r2 x2 of Fig. 1. Fig. 3 is a viewcorresponding to Fig. 1, but with some parts sectioned and others brokenaway. Fig. 4 is a View corresponding to Fig. 2, but showing the drillinserted into a casing tube and showingthe parts of the drill indiderent adjustment. Fig. 5 is a section on the line x5 n35 of Fig. 4.Fig. 6 is a detail in side elevation corresponding in the position ofthe parts to Fig. 5, some parts being broken away. Fig. '7 is a sectionon the line solar/7 of Fig. 2, and Fig. 8 is a detail view of thejaw-closing spring.

The character z indicates a Well-hole which is being bored, and thecharacter c' indicates an incasing tube or pipe.

The head or body ot" the tool 1 is of cylin-` drical form and is adaptedto slide very freely within the casing z'. Atits upper end it is formedwith a reduced and screw-threaded shank 2, to which the tool-operatingpipe 3 is detachably secured.

The chisels or cutters 4 overlap the one with the other at their latinner faces and are provided with tapered stems 5,' which dt in atapered socket 6 in the lower endof the head 1 and are pivotallyconnected bya bolt or pin 7. When the stems 5 are drawn into the socket6, the cutters 4 are held distended laterally or expanded beyond thesides of the head 1 far Venough to cut or drill a hole of greaterdiameter than the casing e'. When the cutters are thus distended,shoulders la at the upper ends thereof project beyond the sides of thehead 1, as shown in Figs. 1 and 3.

The character 8 indicates a U -shaped spring or staple-like link, theends of which are turned outward at 8 and are inserted into suitableseats l formed one in each stem 5. This spring 8` tends to draw thecutters inward.

Mounted Within the head 1 is a quite strong coiled spring 9, one end ofwhich is attached to the spring-staple S and the other end of which isanchored to a screw or pin 10, shown as passed diametrically through theupper end of the head 1. This spring 9 exerts considerable force,tending to draW` the stems 5 up- Ward into close engagement with thesocket 6, and thus to keep the cutters 4 distended or spread out, asshown in Figs. 1 and 3.

Y The bolt or pin Tis provided at one end with a head 11, whichcooperates with a latchspring 12, the upper end of which, as shown, issecured by the said screw 10 andthe free end of which Works in a recess13, cut in the side of the head 1 just above the said head 11. Thepurpose and action of this spring 12 will be considered in thedescription of the operation.

A lock-dog afforded by a short link 14c is pivoted to the extreme upperend of one of the stems 5 and engageable with the notch 15 in theextreme upper end of the other stem to lock the cutters in theirdistended or spread positions. A tripping-plun ger 16, pivoted to thefree end of the dog or link 14, Works freely through a perforation in ahead 17, shown as formed integral with the pivot bolt or pin 7 Theleft-hand side of the head 1 as viewed in Fig. 4 is slotted or cut awayat 18 to ai'ord clearance for the tripping-plun ger 16 and free end ofthe dog 14.

The operation in applying the drill or tool to working position andremoving the same through the casing or tube z is as follows: Thecutters are drawn out from the head 1 and forced together, as shown AinFig. 6, and the free end of thellatch-spring 12 is pressed inward backof the head 11 of the bolt 7, thereby holding the said cutters drawnoutward, as shown in said Fig. 6. While the spring is thus still pressedinward, the tool is inserted into the casing z', and it will be noted byreference to Fig. 4 that the said spring 12 is so bulged outward nearits free end that it will be held in its operative position as long asit remains in said casing. Hence it is evident that the tool may bereadily forced downward through the casing. When the tool has beenforced downward so that its cutters 4 and the spring 12 are carriedbelow the extreme lower end of the casing, the said spring under its ownltension will fly outward out of engagement with the head 11, therebypermitting the spring 9 to draw the stems 5 upward into the socket 6 andforce the cutters outward into the positions indicated by dotted linesin Fig. 5.

It should be noted that when the cutters are drawn downward from thehead 1, as indicated in Figs. 4 and 5, the lower end of thetripping-plunger 16, striking the lower extremity of the slot 18, raisesthe dog 14 out of engagement with the notch 15 and unlocks the two stems5 the one from the other. From this it follows that the two cutters 4will be held spread out until they are drawn outward from the head 1nearly or quite to their extreme positions. When the stems 5 are drawninto the socket 6 nearly or quite to their eXtreme position, the upperend of the tripping-plunger 16 will strike the upper extremity of theslot 1S, and thereby force the dog 14 again into engagement with thenotch 15.

To withdraw the tool from working position, force is applied to draw thesame upward, thereby carrying the shoulders 4 of the cutters 4 againstthe extreme lower end of the casing z', and thus pulling the stems 5 outof the socket 6 until they again reach the positions indicated by dottedlines in Fig. 5 and by full lines in Fig. 6, whereupon the dog 14 willbe again released from the notch 15, the cutters will be forced togetheror inward, and the latch-spring 12 will be again engaged by the head orlug 1l, thereby permitting the tool to be freely drawn upward andoutward through the casing.

It will of course be understood thatthe tool above described is capableof considerable modification within the scope of my invention as hereinset forth and claimed. While it is desirable that the spring-staple 8 orsome other spring should exert a force tending to close the cutters up,still this is not necessary, for the reason that the shoulders 4 beinglocated outward of the pivot 7 will when pressed upon tend to close upthe cutters.

What I claim, and desire to secure by Letters Patent of the UnitedStates, is as follows:

1. In an expansion-drill or boring-tool, the combination withthe head orbody of a pair of cutters having projecting stems pivotally connected atthe upper ends and tting a socket formed in the lower end of said head0r body, a spring normally holding said stems within said socket vand`in turn holding said cutters distended, and a lock-dog normally lockingsaid stems against pivotal movement, which dog is released when thestems are `withdrawn from said socket nearly or quite to their extremepositions.

2. In an expansion-drill or boring-tooLthe combination with a head orbody, of a pair of cutters having projecting stems pivoted at theirinner ends and fitting a socket formed in the lower end of said head orbody, a spring normally holding said stems within said socket and inturn holding said cutters distended, a lockdog pivoted to one of saidstems and engageable with a notch in the other stem to lock'said stemagainst pivotal movements, and a plunger pivoted to the free end ofsaiddog and working in a slot in said y head or body to release said dogwhen said stems are drawn out and lock the same together when the saidstems are drawn into said socket, substantially as described.

In testimony whereof I afx my signature in presence of two witnesses.

RALPH J. BROTHEM.

Witnesses:

A. M. ECKMANN, THEO. S. NELSON.

IOO.

